A number of electrical cables are arranged in an automobile. The electrical cables are also arranged in the electrical connection box, such as a junction box, to form an internal circuit.
For convenience of explanation, a conventional electrical cable and a connection structure between the conventional electrical cable and a terminal will be described by referring to FIG. 6. FIG. 6 is a perspective view of a conventional connection structure between an electrical cable and a terminal.
As shown in FIG. 6, an electrical cable 1 generally includes a twisted core wire 2. The core wire 2 is formed by twisting a number of element wires made of soft copper. An insulation sheath 3, made of vinyl chloride, covers the twisted core wire 2.
In the case where the above electrical cable 1 is arranged in the electrical connection box to form an internal circuit, the electrical cable is pushed into an insulation displacement slot 4a in an insulation displacement terminal 4 in an insulation displacement manner to form a branched connection circuit. The insulation displacement terminal 4 is produced by punching a copper-based metal plate. The internal circuit in the electrical connection box uses a bus bar. The bus bar is produced by punching a copper-based metal plate into a circuit configuration.
Recent, requirements make it desirable to enhance recyclability of junked automobiles. Iron accounts for the largest percentage of an automobile. When the junked automobile is thrown into an incinerator to recover and recycle the iron, the required mixing rate of copper to iron should be less than 0.1%. This prevents the iron from becoming denatured due to a reaction with the copper.
Since the electrical cable 1 is made of soft copper wires, as described above, it is preferable to remove the electrical cable 1 from the car body upon disassembly of the automobile and to separate the electrical cable 1 from the iron-based car body. A wire harness including a group of electrical cables arranged along the car body can easily be separated from the car body. However, the electrical connection box must be disassembled in order to remove the electrical cable from the electrical connection box. This requires extensive manpower and is not practical.
In the case where the internal circuit in the electrical connection box is formed by bus bars made of a copper-based metal plate, the bus bars must be removed from the electrical connection box. This also requires extensive manpower and is not practical.
The insulation sheath 3 of the electrical cable 1 is made of vinyl chloride. Recently, environmental requirements dictate lower utilization of vinyl chloride, which has a chlorine component, in order to suppress halogenation.
In view of the above problems in recycling and in the environment, it is an object of the present invention to improve the material of an electrical cable. The improvement overcomes the problems caused by insulation displacement connections between the improved electrical cable and an insulation displacement terminal.